The user-friendly operation of computers utilizes a graphic user interface, such as e.g. Windows from the Microsoft Company. Different application programs are accessible through such a user interface. A program manager provides graphic symbols in the form of icons to indicate to a computer user which application programs are accessible. Such an icon represents one application program in each case.
The different accessible application programs can potentially process different data formats so that data streams of two or more application programs cannot simply be linked to each other. Data with a first data format, which were output by a first application program, must therefore first be reformatted for use in a second application program so that they can be processed by the second application program.
If the user wishes to link two or more application programs with each other, he or she must first check whether the data streams are compatible. Compatibility in this case means that the data in the first data format, which were output by the first application program, can be processed by the second application program. In this instance the data streams of the first and the second application program are compatible. The application programs exchange compatibility codes by means of an internal protocol.